Re: [racket-users] Annoying run-warnings in DrR 7.5: How to disable?

On 24 Jan 2020, at 14:00, Robby Findler wrote: > In the preferences dialog, in the General tab, the last checkbox is > the one you want. The one for saving files upon switching tabs? > But let me confirm: the reason it is painful to turn on the preference > is that you have to choose a file?

[racket-users] Annoying run-warnings in DrR 7.5: How to disable?

Hi all, One thing I’ve noticed is new in DrRacket 7.5 is the warning dialog that pops up upon hitting Run, saying “The file is not saved; save it before Run?” where may be in some other tab than the one that has focus. This is annoying the heck out of me, as I usually tend to have at

[racket-users] Long-term substitute teaching post available at private school

Dear Racket friends & teachers, I’m taking a semester of leave from my teaching position at Kirby School in Santa Cruz, CA, and the school is looking for a part-time sub to cover my programming class, which I teach based on HtDP. This would be one period, Mondays/Wednesdays/Fridays — usually

Re: [racket-users] Editor task: finding end of code on line

een assuming it is totally language-agnostic. Thanks again, J > Robby > > >> On Tue, Jul 2, 2019 at 11:41 AM Jordan Johnson wrote: >> Dear Racket folks, >> >> I’m trying to implement a keybinding to get me more familiar with the editor >> toolkit. I’m working on

[racket-users] Editor task: finding end of code on line

Dear Racket folks, I’m trying to implement a keybinding to get me more familiar with the editor toolkit. I’m working on modifying the Ctrl+E keybinding so it behaves more like the Ctrl+A keybinding (which, once at the beginning of the line, toggles between the true beginning of the line and

Re: [racket-users] bugs.racket-lang.org down?

On 8 May 2019, at 11:53, Sam Tobin-Hochstadt wrote: > bugs.racket-lang.org was hosted on a server at Northeastern, which > died recently (this resulted in a number of other problems as well). > While we will bring back that data, I would encourage you to submit > bugs at

[racket-users] bugs.racket-lang.org down?

Hi all, I’m unsuccessful in connecting to bugs.racket-lang.org, and downforeveryoneorjustme.com also reports it being down. Is the web server there not running for some reason? Best, Jordan -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To

[racket-users] 2htdp/image: Alpha blending

Hi all, The docs for image->color-list say: > The list of colors is obtained by drawing the image on a white background and > then reading off the colors of the pixels that were drawn. According to that description, if I evaluate... > (first (image->color-list (square 2 'solid (make-color

Re: [racket-users] How do you make students submit programming assignments online for automatic tests?

On Feb 20, 2019, at 10:40, 'John Clements' via Racket Users wrote: > One solution would be to use the command-line version of Racket’s > handin-server, which is language-agnostic to the degree that it can just > submit arbitrary files to the server, and what happens on the back end is up > to

Re: [racket-users] Finding the right font%

Ok, thanks for the replies! —Jordan > On Feb 14, 2019, at 07:57, Matthew Flatt wrote: > > I have noticed that some fonts I used to use became inaccessible on Mac > OS in v7.0, which is when we upgraded Pango. In my case, the relevant > change seems to be that Pango became better at tracking

[racket-users] Finding the right font%

Hi all, I’m using a typeface (Espinosa Nova ) comprised of twelve distinct fonts. When I use the pict or 2htdp/image library to create an image of some text — e.g., > (text "Foo bar!" 24 "Espinosa Nova") ; pict lib — Racket gives me

Re: [racket-users] Some concern about ChezScheme...

On Feb 6, 2019, at 11:28, Matthias Felleisen wrote: > On Feb 6, 2019, at 2:22 PM, 'Paulo Matos' via Racket Users > wrote: >> Interestingly according to Matt these ideas were already floating around at >> his uni as early as 98? > My recollection is that Kent taught with this approach because

[racket-users] SXML/SXPath: selecting a node, keeping small subset of children

Hi all, Is there an idiom in SXPath/SXSLT for selecting a node and keeping only a small subset of its children by name? E.g., if, somewhere in my document, I have ...50 other elements... ... ...more

Re: [racket-users] Making evaluators / handin server setup

Hi Matthew et al., Following up some work from last fall: On Oct 6, 2018, at 15:58, Matthew Flatt wrote: > At Wed, 26 Sep 2018 15:57:12 -0700, Jordan Johnson wrote: >>> (require racket/sandbox) >>> (make-evaluator "beginner-lang.rkt") >> . . ../../../../../

Re: [racket-users] handin-server: reader used in checker modules

> On Oct 17, 2018, at 11:30, Shu-Hung You > wrote: >> >> Would it help if in the check module you use `=' as the equality test, >> or specify #e10.25 instead? > > Success! > > Specifying > (!test (hour-angle 12 20 30) #e10.25) > produces the behavior

Re: [racket-users] handin-server: reader used in checker modules

On Oct 17, 2018, at 11:30, Shu-Hung You wrote: > > Would it help if in the check module you use `=' as the equality test, > or specify #e10.25 instead? Success! Specifying (!test (hour-angle 12 20 30) #e10.25) produces the behavior I expected, correctly comparing the numbers. Thanks, all!

Re: [racket-users] handin-server: reader used in checker modules

>> So, what aspect of the language config would be responsible for 41/4 not >> equaling 10.25? > > Welcome to Racket v7.0.0.20. >> (= 41/4 10.25) > #t >> (read-decimal-as-inexact #f) >> (= 41/4 10.25) > #t > > Do you perhaps print and read the result? Nope. The code that’s generating the

Re: [racket-users] handin-server: reader used in checker modules

> On Oct 17, 2018, at 10:35, Matthias Felleisen wrote: >> (check-expect (+ 10 .25) 10.25) >> >> errors with check-expect’s message about not comparing inexact numbers, but >> in DrRacket+BSL the decimals are treated as exact numbers. >> >> What do I need to change in the checker, in

[racket-users] handin-server: reader used in checker modules

Hi all, In my last thread regarding the handin server, Matthew suggested: > A workaround is to use `'lang/htdp-beginner` as the language instead of > `'(special beginner)`. That happens to avoid a redundant and > troublemaking `require`. So, I’m using 'lang/htdp-beginner in an assignment’s

[racket-users] Making evaluators / handin server setup

Dear Racketeers, I’m writing about difficulties using make-evaluator in Racket v7.0 with a module that selectively (or not) re-exports bindings from an existing language. This is related to work I’m doing with the handin server. - the short version - Create this file, and use as follows:

Re: [racket-users] Strange window behavior in OSX Yosemite DrRacket

-users@googlegroups.com <mailto:racket-users@googlegroups.com>> wrote: > > > > On Jan 25, 2018, at 8:48 AM, Jordan Johnson <j...@fellowhuman.com > > <mailto:j...@fellowhuman.com>> wrote: > > > > Hi all, > > > > One of my students is

[racket-users] Strange window behavior in OSX Yosemite DrRacket

Hi all, One of my students is observing some strange behavior involving the Program Contour pane of DrRacket. He’s using v6.11 on OS X Yosemite 10.10.5. This is the top-right corner of his DrR window, with Program Contour open: Upon pressing Cmd+U to hide it, this is what happens:

Re: [racket-users] 2htdp/universe: behavior of dual shift keys

Thanks, Alex. A little more digging, and here’s some more info; I’m hoping this will be enough for the maintainers of 2htdp/universe to track down what’s going on. In 2htdp/private/check-aux.rkt in the htdp-lib package, I opened a REPL and ran this code: > (require racket/gui) > (define f

[racket-users] 2htdp/universe: behavior of dual shift keys

Hi all, The attached program exhibits some odd behavior in 2htdp/universe, and I want to track down where it’s coming from. AFAICT it’s not an error in the program itself, but if I’m mistaken I’d be pleased to have confirmation that the cause isn’t in the OS or the 2htdp/universe library.

Re: [racket-users] DrRacket (6.11) issue on Windows 10

There’s also (Windows key)+(left/right arrow), which will move the window to the left/right half of the current display, and (Windows key)+Shift+(left/right arrow), which cycles it to the previous or next display (in case, e.g., the window is on a different display because the student had the

Re: [racket-users] Connecting a language and its reader

this makes sense depends, of > course, on the particulars of the language you're defining. > > -Philip > >> On Sun, Oct 1, 2017 at 2:50 PM, Jordan Johnson <j...@fellowhuman.com> wrote: >> Hi all, >> >> I’ve been putting together a litt

[racket-users] Connecting a language and its reader

Hi all, I’ve been putting together a little language to learn more about how the Racket #lang ecosystem works, and I’m hung up on bundling up the language as a collection. I’m not sure I correctly understand the point where the reader attaches to the macros that specify how to expand the

Re: [racket-users] document as fn from strings to HTML/text

Fantastic. Thank you, Neil & Ben. Regards, Jordan > On Sep 28, 2017, at 11:09, Neil Van Dyke wrote: > > If you don't care whether you edit in HTML syntax, and you'd like a slightly > more programming-ish interface, there's also: >

[racket-users] document as fn from strings to HTML/text

Hi all, Problem: I want to generate many documents from a source template (of which only a few small parts change, from doc to doc) and many groups of values. Ideally I’d like to be able to write files like this: *** template *** ... @(for/list ([item my-list]) (li item)) ... *** list

[racket-users] table lookup shorthands?

Hi all, I’m writing some music-related code for which I find myself using a lot of lookup tables, following the pattern of making an alist or hash table and then writing a function that consults the table. I wound up writing a macro for this pattern; one example of its use is: ;; key->fifths

Re: [racket-users] ~literal vs ~datum

On Aug 1, 2017, at 11:34, Jens Axel Søgaard wrote: > The binding information is attached a syntax object during expansion. > In your example the #'(define x y) haven't gone through expansion, > so you do not get what your expected result. > > However we can change your

[racket-users] ~literal vs ~datum

Hi all, Reading the documentation on ~datum in syntax/parse, I see: The ~datum form is useful for recognizing identifiers symbolically, in contrast to the ~literal form, which recognizes them by binding. That makes sense to me. But then I see: > (syntax-parse > > (let > > ([define

Re: [racket-users] Hint on opening enclosing directory of current file from DrRacket

IIRC on windows, at the cmd prompt (and hence maybe through DrR's "system" procedure) you can type "explorer ." to obtain the same behavior. Cheers, Jordan > On Jun 28, 2017, at 5:38 PM, James wrote: > > >> On Jun 28, 2017, at 5:42 PM, Glenn Hoetker wrote: >> >>

Re: [racket-users] Re: Proper non-tail recursion?

On Apr 25, 2017, at 6:09 PM, Matthias Felleisen wrote: > While I am at it, let me advocate PITCH as the slogan for Proper > Implementation of Tail Calls. (Where does the H come from? I added it to make > a complete word.) Proper Implementation of Tail Call Handling? :)

Re: [racket-users] Should I keep all of the definitions from HTDP2e in one definitions save file?

If I were doing it from scratch, I would keep one file for each section or each grouping of exercises. One big file for the whole book is a bit much, especially given that sometimes definitions are revisited with similar names. And one file per exercise is probably too small, and could make it

[racket-users] TCP listening & custodians

Hi all, The code below is a simple server based on the web server in the “More: Systems programming in Racket” tutorial. This behavior is puzzling me: I run the server (from the OS X Terminal) and connect a client. After a wait, the client is disconnected by the timeout (shown in red). I halt

[racket-users] Detecting EOT when reading a TCP port

Hi all, Quick question: Given a listener and input port defined thus: (define listener (tcp-listen port)) (define-values (in out) (tcp-accept listener)) while reading lines of text, what’s the correct way to detect an EOT (^D or U+0004) character? This “obvious” solution does

[racket-users] Limiting memory for raco

Hi all, Is it possible to limit the memory that raco uses for running builds (beyond whatever reduction I might get by using the -j option to reduce the number of parallel jobs)? If so, how? Thanks, jmj -- You received this message because you are subscribed to the Google Groups "Racket

Re: [racket-users] Order of argument conventions, or ... conventions of argument ordering

1) With many of these functions, there's usually an imaginary preposition there, when I read most of them functions: sort ls by > cons X onto ls remove X from ls map f over ls 2) Any "-ref" function — list-ref, vector-ref, hash-ref — has the object first. Longstanding Scheme/lisp convention,

Re: [racket-users] Package catalog - can't connect

> At Mon, 18 Apr 2016 14:32:20 -0700, Jordan Johnson wrote: >> ssl-connect: connect failed (error:14090086:SSL >> routines:ssl3_get_server_certificate:certificate verify failed) >> context…: [stack trace follows] > > I've seen these kinds of problems where the set of

[racket-users] Package catalog - can't connect

Hi all, I just downloaded Racket 6.4 onto my VPS (running Debian 6.0), and when I try to install packages (with raco pkg), I’m getting failures to connect to the server. First this: ssl-connect: connect failed (error:14077410:SSL routines:SSL23_GET_SERVER_HELLO:sslv3 alert handshake failure)

Re: [racket-users] Playing sound

On Apr 6, 2016, at 15:18, John Clements wrote: > 1) The “stop” procedure is a giant end-of-the-world hammer; I wouldn’t expect > it to be useful while a program is running. OK. It had that feel. > 2) I hesitate to suggest this, but there is a “pstream-set-volume!”

Re: [racket-users] Playing sound

Hey, so I’m now looking at how to set up background music in rsound with the ability to switch tracks. Below is the suggestion from John Clements that seems right: >> I’m guessing you’re looking for an imperative API that looks something like >> this: >> >> (start-playing! stream sound at-time

Re: [racket-users] Playing sound

Hi John, Thanks for the reply. > If you’re concerned about test failures in pkg.racket-lang.org… well, my test > cases try to load the shared libraries and play sound, so that’s not possible > in pkg.racket-lang.org’s environment. Oh, good. That's less of a worry then. Will the separate

[racket-users] Playing sound

Hi all, I'm looking at audio again because I have a student doing a game project for which he wants background music to play — and I'm feeling some trepidation based on most of the audio-tagged packages on pkgs.racket-lang.org showing some test failures or other build problems. His minimal

Re: [racket-users] A template/example to use to build a workflow illustration/flowchart in slideshow

Yes. The slideshow tutorial referenced near the top of http://docs.racket-lang.org/slideshow/index.html ("Run Tutorial") incorporates a slideshow in which you can inspect the source. Best, Jordan > On Jan 13, 2016, at 5:10 PM, C K Kashyap wrote: > > Dear group, > > I am

Re: [racket-users] racket users fight for their right to colon keywords

On Oct 23, 2015, at 8:30 AM, Greg Hendershott wrote: > Keyword arguments: Although I'm comfortable in the #: camp, I can > understand people preferring :foo over #:foo for the reason that it is > faster to type. #: requires two shifted chars. If you touch type you >

[racket-users] Multiple colorschemes for multiple DrR versions?

Hi all, Is there a way to specify that DrRacket use a certain color scheme for a certain version, or to dynamically choose a color scheme at startup? It occurred to me that since I sometimes run a DrRacket built from the nightly snapshots and sometimes run the latest stable build, it’d be nice

Re: [racket-users] Frog/Scribble: h* tag substitution

On Aug 28, 2015, at 9:06 AM, Greg Hendershott greghendersh...@gmail.com wrote: Yes. It's happening in Frog, where the HTML generated by Scribble is adjusted in a few ways: ... Maybe you'll agree that behavior is OK, now that you know what's going on and why? This takes care of my

[racket-users] Frog/Scribble: h* tag substitution

Hi all, I’m using Greg Hendershott’s Frog[1] tool for my web site, and since I know I’m outputting HTML I sometimes want to be able to tell Frog/Scribble, “Just use this HTML tag here.” I’ve looked at the docs on implementing styles[2], and came up with this attempt: ;; string? - (string?

[racket-users] Scribble: Wrap text in examples/interactions?

Hi all, Is there a way to get long lines of text in a Scribble @examples block to wrap? (Perhaps looking something like DrRacket’s wrapped lines?) Thanks, jmj -- You received this message because you are subscribed to the Google Groups Racket Users group. To unsubscribe from this group and

[racket-users] TR: Option values

Hi all, Writing TR code, I find that the more I use the Option type, the more I want something like Haskell’s Maybe monad. Is there any existing tool I’m missing, that provides for applying functions to values of type (Option x), by propagating failures? If not, would it be sensible to

Re: [racket-users] Scribble undefined tags

that all Scribble docs are rendered into the main docs directory for your installation, thus breaking local paths that wander outside your 'scribblings' subdirectory. On Fri, Jul 24, 2015 at 8:58 AM, Jordan Johnson j...@fellowhuman.com wrote: Hi all, I have a file *main.scrbl* in the same

[racket-users] Scribble undefined tags

Hi all, I have a file main.scrbl in the same directory as a file main.rkt. In the .scrbl file, I have (require (for-label main.rkt)) and several defproc and defstruct* forms. For some reason, one of my defstruct* forms works as expected, while all of the other defstruct* and defproc forms

[racket-users] TR: require/typed and parametric polymorphism

Hi all, If I’m reading the docs source correctly, it looks like it’s impossible to use require/typed to attach a parametric type to an import. Is that right? I’m also a bit curious if that’s because adding that capability is a difficult or impossible proposition. Cheers, jmj -- You

[racket-users] TR typed-racket-more library docs

Hi all, One thing I’ve noticed in working with Typed Racket is that some of the libraries on the “Libraries Provided with Typed Racket http://docs.racket-lang.org/ts-reference/Libraries_Provided_With_Typed_Racket.html” docs page have type definitions that aren’t documented anywhere, but that

Re: [racket-users] Moving an image with the keyboard

Hi Patrick, The problem you’re up against is that in the code you’ve attached, we don’t have a clear picture of what the signatures for your functions are, nor of the “world” upon which big-bang operates. Standard practice in HtDP-based courses dictates that every big-bang program should have

[racket-users] ANN: cookies library for clients and servers

Hi all, This weekend I added to the package catalog a set of libraries (named net-cookies) for managing cookies as per RFC6265, the most recent cookie RFC. Documentation: http://pkg-build.racket-lang.org/doc/cookies/index.html Source: https://github.com/RenaissanceBug/racket-cookies Examples